The conventional optical waveguide modules are arranged to comprise an optical waveguide device, which is utilized for branching, coupling, or the like of signal light, for optically interconnecting optical fibers being transmission lines, and a case for enclosing the optical waveguide device therein. Further, a space between the case and the optical waveguide device is filled with a buffer protector. The buffer protector functions to absorb impact or the like exerted from the outside of the case on joint portions and the like between an optical waveguide incorporated in the optical waveguide device and optical fibers.
Here, the above optical waveguide device comprises a waveguide substrate having an optical waveguide provided in its upper surface and having the function of branching, coupling, etc. of signal light, a silicon V-grooved support member (first support member) for optically connecting one end of the optical waveguide with one end of an input optical fiber, attached to the tip of the input optical fiber, and a silicon V-grooved support member (second support member) for optically connecting the other end of the optical waveguide with one end of an output optical fiber, attached to the tip of the output optical fiber. The first and second support members are fixed to the both end faces of the waveguide substrate with the optical waveguide being axially aligned with the input and output optical fibers (or in an optically interconnected state).
The structure of optical waveguide module as described above is disclosed, for example, in Japanese Laid-open Patent Application No. 5-27139.